On a FW
setup a sump doesn't serve the same purpose as on a SW
setup. It adds water volume, which when SG
raises quckly helps a lot, but on FW SG
isn't a concern.
The other beni to a sump is that they are a way to hide your heaters, filters, pumps etc. In a small 10 gallon tank this could be handy actually. It all depends on what you want to keep though.
For the most part, I'd say if you keep a 10 gal FW
tank, don't worry to much about a sump, unless you have a specific reason to.